The invention relates to a method of producing a film of an yttria-alumina complex oxide, a film of an yttria-alumina complex oxide, a sprayed film, a corrosion-resistant member and a member effective for reducing particle generation.
In semiconductor manufacturing systems requiring a super clean state, halogen-based corrosive gases such as chlorine-based gases and fluorine-based gases are used as deposition gases, etching gases and cleaning gases. For example, these gases are used as cleaning gases for a semiconductor composed of a halogen-based corrosive gas such as ClF3, NF3, CF4, HF and HCl after the deposition stage in a semiconductor producing system, such as a hot CVD system. Further, halogen-based corrosive gases such as WF6, SiH2Cl2 or the like are used for film formation in the deposition stage.
Further, in film-forming and etching stages of CVD or PVD processes, the chemical reactions for film formation or etching produce by-products, which are deposited onto a susceptor, an electrode or the parts constituting the chamber. Particularly, in a so-called cold wall type system, the chamber wall is low in temperature, so that particles may be easily deposited onto the cold chamber wall. Although such deposits are subjected to wet or dry cleaning processes at predetermined intervals, excessive deposits may fall or be moved onto a semiconductor wafer, resulting in instability of semiconductor processing or reduction of the production yield.
To prevent falling particles, it has been known to apply shot peening or blast treatments using glass beads on the surface of a metal plate to increase the surface roughness, so that the retention force of the metal surface may be improved.
It has been thus desired to form a film that is highly resistive against halogen-based gases or plasmas and which is stable over a long time period on a member used for a semiconductor-producing system, such as a member contained in the chamber or the inner wall surface of the chamber. Further, when by-products are deposited on a member contained in the system or the inner wall surface of the chamber, it is desired that the deposited by-products are retained thereon for a long time period.
The assignee filed a Japanese patent application P2001-110, 136. According to the disclosure, it is possible to form a film of an yttria-alumina complex oxide on a substrate by spraying and to provide a high anti-corrosion property against a halogen-based gas plasma, thus preventing the particle generation. The corrosion-resistant film, however, might leave the following problems. That is, cracks may be induced in the film depending on the conditions for spraying. The sprayed film may be subjected to a heat treatment at a high temperature. Such heat treatment may induce cracks in the film. If cracks are generated in the film of an article having a substrate and the film, such film may be easily peeled from the substrate to generate particles and reduce the anti-corrosion property against a corrosive substance. The resulting article may be undesirable, thus reducing the production yield.